Bartonella spp. seroprevalence in tick-exposed Swedish patients with persistent symptoms

Abstract

Background Bartonella spp. are emerging pathogens transmitted by arthropod vectors, possibly including ticks. We have investigated signs of bartonellosis in Swedish patients with presumed tick-bite exposure and symptom duration of at least 6 months. Methods Serological testing for Bartonella henselae and Bartonella quintana was performed in 224 patients. Symptoms, tick exposure, evidence of co-infection and previous treatments were evaluated. Seropositive patients were compared to a matched group (twofold larger and negative serology) from the same study cohort. Results Seroprevalence was 7% for B. henselae and 1% for B. quintana, with one patient testing positive to both agents. Tick bites were reported by 63% of the patients in the seropositive group and 88% in the seronegative group and presumed tick exposure was more common in the seronegative group. Animal contact was equally common in both groups, along with reported symptoms. The most common symptoms were fatigue, muscular symptoms, arthralgia and cognitive symptoms. Exposure to co-infections was evenly distributed in the seropositive and seronegative groups. Conclusions Antibodies to Bartonella were more common in this cohort of patients than in cohorts of healthy Swedish blood donors in previous studies but lower than those in blood donors from southern Europe. Positive Bartonella serology was not linked to any specific symptom, nor to (suspected) tick-bite exposure. Graphical abstract

Molecular Survey of Bartonella Species in Stray Cats and Dogs, Humans, and Questing Ticks from Portugal

“…has been previously detected in veterinary practitioners by a cPCR method targeting the ITS gene [ 43 ] and on cat owners from Spain (using the same method) [ 30 ], with a prevalence of 28% and 27%, respectively. For serology assessments, an incidence of 7% was reported for B. henselae and 1% for B. quintana on a survey performed in Sweden, with a sample of 224 patients [ 44 ], while another survey performed in Poland had a reported incidence of 23% seropositive cases for B. henselae and 2.85% for B. quintana from 105 tested subjects, composed of 65 blood donors and 40 patients suffering from musculoskeletal symptoms [ 45 ]. Despite these reports, the samples screened in the present study were negative for the bacteria, also including the blood cultured samples.…”

“…DNA in ticks and, more recently, the reports of Bartonella spp. seroprevalence in tick-exposed patients from Sweden and Poland, although the last one lacked statistical significance [ 44 , 45 ], which has put them on the spot [ 50 ]. In the present study, despite sampling over 260 ticks collected in different locations across Portugal mainland, Bartonella sp.…”